Center for Advanced Research in Sleep Medicine, Sacré-Coeur Hospital, Montreal, Quebec, Canada.
Pediatrics. 2013 Jun;131(6):e1874-80. doi: 10.1542/peds.2012-2284. Epub 2013 May 27.
To determine the relative contributions of genetic and environmental factors on daytime and nighttime continuous sleep duration at 6, 18, 30, and 48 months of age, and to identify different subgroups of children who followed different daytime and nighttime sleep duration trajectories and to investigate their etiology.
The current study included 995 twins (405 monozygotic and 586 dizygotic) of the Quebec Newborn Twin Study recruited from the birth records of the Quebec Statistics Institute. Daytime and nighttime sleep was assessed through maternal reports at 6, 18, 30, and 48 months of age. A semiparametric modeling strategy was used to estimate daytime and nighttime sleep duration trajectories. Quantitative genetic models were used to examine to what extent genetic and environmental factors influenced daytime and nighttime continuous sleep duration.
Genetic modeling analyses revealed environmental influences for all daytime sleep duration trajectories. In contrast, strong genetic influences were found for consolidated nighttime sleep duration (except at 18 months and for the short-increasing sleep duration trajectory).
This is the first indication that early childhood daytime sleep duration may be driven by environmental settings, whereas the variance in consolidated nighttime sleep duration is largely influenced by genetic factors with a critical environmental time-window influence at ∼18 months.
确定遗传和环境因素对 6、18、30 和 48 个月龄儿童日间和夜间连续睡眠时间的相对贡献，并识别遵循不同日间和夜间睡眠时间轨迹的不同儿童亚组，并探讨其病因。
本研究纳入了来自魁北克新生儿双胞胎研究的 995 对双胞胎（405 对同卵双胞胎和 586 对异卵双胞胎），这些双胞胎是从魁北克统计局的出生记录中招募的。日间和夜间睡眠通过母亲在 6、18、30 和 48 个月龄时的报告进行评估。采用半参数建模策略来估计日间和夜间睡眠时间轨迹。采用定量遗传模型来研究遗传和环境因素对日间和夜间连续睡眠时间的影响程度。
遗传模型分析显示，所有日间睡眠时间轨迹都受到环境影响。相比之下，整合的夜间睡眠时间则受到强烈的遗传影响（18 个月和短时间增加的睡眠时间轨迹除外）。
这是第一个表明儿童早期日间睡眠时间可能受环境因素驱动的迹象，而整合的夜间睡眠时间的变化主要受遗传因素影响，在约 18 个月时受到关键的环境时间窗口影响。
